1. Field of the Invention
This present invention relates to electric power source devices to be used in hybrid vehicles, electric vehicles etc.
2. Description of the Related Art
Hybrid vehicles and electric vehicles usually use electric power source devices such as charging devices and direct current to direct current (DC-DC) converters. Such a charging device is usually equipped with the DC-DC converter. For example, a patent document Japanese patent laid open publication No. 2012-213309 has disclosed a conventional electric power source device. The electric power source device is generally comprised of a transformer, semiconductor elements, a smoothing circuit and a base plate. Such a transformer decreases and/or increases a direct current power (DC power) to a specified DC power. The semiconductor elements rectify an output voltage of the transformer. The smoothing circuit performs a process of smoothing the output voltage which has been rectified by the semiconductor elements. The transformer, the semiconductor elements, the smoothing circuit etc. are mounted on a mounting surface of the base plate. The semiconductor elements and at least one of the transformer and the smoothing circuit are stacked and arranged in a direction of a normal line of the mounting surface of the base plate. This arrangement reduces the overall surface area of the mounting surface of the base plate in a horizontal direction of the base plate.
However, the conventional technique disclosed in the patent document described above may cause the following problem. The electric power source device disclosed in the patent document 1 contains components having a different size. This often generates an unusable space around the components having a small exterior size when the components are stacked on the mounting surface of the base plate in order to make a stacked section. Accordingly, there is a demand to reduce the unusable space and effectively utilize the overall space on the mounting surface of the base plate in the electric power source device.